It's happened on 2 of 2 syncs so far - I've only been back to using Lr Mobile for two days. So I'll have to wait a while to be able to let you know if it happens every time. I would prefer not to try it with a new catalog, because I don't want to have to resync the 7,000 Smart Previews I already have synced with the cloud - am I right that's what will happen if I set up a new synced catalog temporarily? If we run out of other options to try, I'll do that though!

Here's my workflow:

Shoot a bunch of DNGs with the Lr camera on Android.

Let them sync up with CC.

Open Lr Classic, let it sync with CC.

There appears to be nothing faulty with the images that are available in Lr Web. If I download the DNGs from Lr Web, Classic will import them fine. Alternatively I can overwrite the synced files outside of Classic, reload Classic and they also work fine.

Would you like to wait until I've been shooting with Lr Mobile a few more days to see how frequently it happens, before we pursue this?